The invention relates to an apparatus and method for deactivating an airbag in a motor vehicle.
The motor vehicle has at least one vehicle seat, to which a child seat, placed upon it, can be fastened, with a device being provided to deactivate an airbag located in front when the child seat is mounted. In order to allow a device of this kind to be retrofitted simply and economically even in existing mass-produced vehicles, the device is constituted by a tongue additionally mounted on the child seat and a latch in an active connection with a central triggering unit, with the airbag being deactivated by inserting the tongue into the latch and reactivated when the connection is broken. For this purpose, the latch has an integral sensor connected by a lead with a central triggering unit. The sensor is constructed in a redundant manner in order to improve reliability.
Advantageously, the certainty that the airbag will be shut off when the child seat is mounted is considerably increased by this measure so that a child sitting in the child seat is better protected against the airbag being triggered.
According to the present invention, an apparatus for deactivating an airbag in a motor vehicle is provided, comprising: at least one vehicle seat; a child seat which is mountable on said vehicle seat; a device for deactivating an airbag located in front of the child seat when the child seat is mounted on said vehicle seat, said device comprising a tongue mounted on the child seat, and a latch in an active connection with a central triggering unit, said airbag located being deactivated by inserting the tongue into the latch and being reactivated by releasing the tongue from the latch, said latch having an integral sensor connected by a connecting lead to the central triggering unit, said sensor being made in redundant form.
According to the present invention, a method for deactivating an airbag in a motor vehicle having at least one vehicle seat and a child seat which is mountable on said vehicle seat is provided, comprising: providing a device for deactivating an airbag located in front of the child seat when the child seat is mounted on said vehicle seat, said device comprising a tongue mounted on the child seat, and a latch having an integral sensor in an active connection with a central triggering unit, said sensor being made in redundant form; deactivating said airbag via said central triggering unit when said tongue is inserted into said latch; and reactivating said airbag via said central triggering unit when said tongue is released from said latch.
According to certain preferred embodiments, the redundant system is formed by using duplicate sensors. This double installation of the sensor significantly reduces the probability that the insertion of the tongue into the latch will not be recognized by a defective sensor.
According to certain preferred embodiments, a switch element is provided in the sensor. With a switch element, for example a switch or a reed contact, the insertion of the tongue into the latch can be recognized very reliably in a known manner.
According to certain preferred embodiments, the sensor is formed as a chain of two resistances connected in series, with the switch element bridging one of the resistances. With such a design for the sensor, in addition to the unswitched state of the switching element (both resistances active) and the switched state of the switching element (only one resistance active), a break in the lead (infinite resistance) and a short circuit (resistance=0) can be identified.
According to certain preferred embodiments, the resistance chains of a redundant system of sensors are connected in parallel. By virtue of the two states described above, additional identification can be performed to determine whether one of the two sensors or one of the switch elements contained in the two sensors is defective.
According to certain preferred embodiments, the central triggering unit evaluates the signal from the sensor and permits triggering of the airbag located in front only if the evaluation indicates beyond a doubt that the tongue is not inserted into the latch. This evaluation is preferably intended to be performed by comparing a total resistance of the sensor with a set value range. In this way, in case of doubt, an airbag located in front of the child seat will not be triggered, so that even if a child seat is in fact mounted but this condition is not recognized because of a defect, a child sitting in the child seat will be protected against the airbag being triggered.